1. Field of the Invention
The present invention relates to a control apparatus of a single-lens reflex camera, and more precisely, it relates to a control apparatus of a single-lens reflex camera in which a film (frame) advance speed is increased in a continuous photographing mode.
2. Description of the Related Art
There is a known single-lens reflex camera which has an automatic winder for continuous photographing. In such a known single-lens reflex camera, in order to take a picture of a second and subsequent frames, the subsequent shutter release operation can start only when the film (frame) is advanced and the mechanical charge is completed.
The "mechanical charge" referred to herein includes a mirror charge for moving a mirror down to a lowermost position (charge completion position or viewing position) against a spring which biases the mirror upward toward a photographing position, a shutter charge for returning the leading and trailing curtains of a shutter to their respective initial positions against respective springs which move the leading and trailing curtains, and a diaphragm charge for moving a diaphragm lever for stopping-down toward an open position against a spring which biases the diaphragm lever in the stopping-down direction. When these charges are finished, or charged the finished states are maintained by respective mechanical engaging members.
After the mechanical charges are completed and the mechanical engaging members are engaged, the photographing (releasing) occurs by sequentially disengaging the mechanical engaging members. Accordingly, in a continuous photographing mode, the photographing operations for frames after the first frame are commenced when all of the mechanical charges are finished and the engagement of the mechanical engaging members are completed.
In a conventional single-lens reflex camera, as mentioned above, generally speaking, the mirror charge is completed before the shutter charge is completed, since the spring for driving the mirror is usually weaker than the spring for moving the shutter and since the black-out time in which no image can be visually confirmed through a finder should be as short as possible.
However, in a continuous photographing mode in a known single-lens reflex camera, the release operation commences after all the mechanical charges are finished. Consequently, there is a limit to a reduction of time interval from the completion of the exposure of the one frame to the commencement of exposure of a subsequent frame. The time interval will be referred to as a "frame advance speed" hereinafter. Namely, in a conventional single-lens reflex camera, since the mirror charge is released after the shutter charge is completed and the shutter charge is then released after the upward movement of the mirror ends, the frame advance speed is decreased by a time delay corresponding to a space of time between the completion of the mirror charge and the completion of the shutter charge.